Re: [PATCHv2 3/3] reiser4: mark pages created during tail2extent conversion as dirty.

[Edward Shishkin <edward.shishkin@gmail.com>]

On 11/09/2015 01:18 PM, Edward Shishkin wrote:
> On 10/25/2015 01:02 AM, Ivan Shapovalov wrote:
>> This is responsible for an oops in v4.2 in
>> write_jnodes_to_disk_extent() -> set_page_writeback().


As to me, this patch doesn't prevent the oops,
so someone else forgets to set pages dirty...

Thanks,
Edward.


>>
>> The pages needs to be marked dirty before marked writeback.
>>
>>  From a similar problem in f2fs:
>> "The cgroup attaches inode->i_wb via mark_inode_dirty and when
>> set_page_writeback is called, __inc_wb_stat() updates i_wb's stat.
>>
>> So, we need to explicitly call set_page_dirty->__mark_inode_dirty in
>> prior to any writebacking pages."
>>
>> Signed-off-by: Ivan Shapovalov <intelfx100@gmail.com>
>> ---
>>   fs/reiser4/plugin/file/tail_conversion.c | 1 +
>>   1 file changed, 1 insertion(+)
>>
>> diff --git a/fs/reiser4/plugin/file/tail_conversion.c 
>> b/fs/reiser4/plugin/file/tail_conversion.c
>> index 7542c03..c856b73 100644
>> --- a/fs/reiser4/plugin/file/tail_conversion.c
>> +++ b/fs/reiser4/plugin/file/tail_conversion.c
>> @@ -175,6 +175,7 @@ static int replace(struct inode *inode, struct 
>> page **pages, unsigned nr_pages,
>>                                   i_mapping));
>>           if (result)
>>               break;
>> +        set_page_dirty_notag(pages[i]);
>
>
> So, at this point the page is dirty but not uptodate.
> I am confused with this. Why not to set the page
> uptodate right before setting it dirty? At this point
> everything has been copied already, so the page is
> in fact uptodate. Could you please try this?
>
> Thanks,
> Edward.
>
>
>>           unlock_page(pages[i]);
>>           result = find_or_create_extent(pages[i]);
>>           if (result) {
>